Piston and rod connection for pumps



March 2, 1943. v HEFTLER 2,312,819'

PISTON AND ROD CONNECTION FOR PUMPS Original Fi led Jan. 7,1941 3 Sheets-Sheet 1 a a a: i i 2: F g 1 a I 27 I I 52 March 2, 1943 v. R. HEFTLER PISTON AND ROD CONNECTION FOR PUMPS Original Filed Jan. 7, 1941 3 Sheets-Sheet 2 March 2, 1943. v, R. HEFTLER PISTON AND ROD CONNECTION FOR PUMPS Original Filed Jan. 7, 1941 s Sheets-Sheet 5 v 0 rill 116 11a be as 4 "INVENT n ing application No. 373,459, filed January 7, 1941 point of view with the pump Patented Mar. 2, 1943 2,312,819 rrs'roN AND- ROD [CONNECTION FOR PUMPS Victor E. Heftler, GrossePointe Park, Mich;

Application January 7, 1941, Serial No. 373,459; which is a division of application Serial No. 348,431, July 30, 1940. Divided and this application August 8, 1942, Serial No. 454,166

4 Claims.

This application is a division of my co -pendwhich latter is a division of my co-pending application No. 348,431, filed July 30, 1940.

It is an object of this invention to provide a.

simple and inexpensive construction for the accelerating pump usually provided in carburetors.

Fig. 1 is a side elevation of a carburetor "embodying my invention, viewed from the lower side ofFig.2. f

Fig. 2 is a plan view, with one half of the cover removed.

Fig. 3 is a front elevation, viewed from the left side of Fig. 2, with some portions cut away showing the pitson of the accelerating .pump in its upper position. s

Fig. 4 is a fragmentary elevation from the same piston in its lower position. w I I Fig. 5 is a so-called exploded View, in perspective and on an enlarged scale, of parts ofthe accelerating pump.

Fig. 6 is an elevation, viewed from the right side of Fig. 2, with some portions in cross section along parallel lines 6a, 6b, 6c and 6d of Fig. 2.

Fig. '7 is a partial cross section along the polygonal line 1'I of 2.

Fig. 8 is a .plan view of the washer and valve retainer.

This invention is described as applied to a downdraft carburetor, comp-rising a throttle housing member 2|, provided with a flange 22 for attachment to an engine manifold, not shown, in the well known manner, over which is secured a mixing chamber body member 23, which supports a cover member 24, these three main parts being fastened to one another, by screws for instance. A heat insulating gasket '52 is preferably inserted between the throttle housing 2! and the mixing chamber body member 23.

The air supply enters through conduit 25 in the cover member 24, being controlled by choke valve 21. Conduit 26 registers with conduit (Fig. 6) in the mixing chamber body member 23, which leads to conduit 3| in the throttle housing member 2 I.

A throttle valve 32, mounted on shaft 33, controls the passage of the mixture through the ca burttor. The means used to actuate the throttle are not shown, they may consists of a lever fastened to shaft 33. To limit the movement of the throttle there is fastened on shaft 33 a lever 34, provided with lugs and. 36. Lug 35 co-operates with stop pin 31 to limit the opening movement, while a screw threaded in lug 36 co-operates with part 3%: to limit adj'ustably the closing movement. r v

Formed in the mixing chamber body member is constant level fuel chamber 82. A pair of floats symmetrically located with reference .to the median plane of the carburetor is used 'to control a fuel inlet in the well known manner. One of these floats is shown at 35 on Fig. 2.

The main normal mixture supply of fuel is effected through a double venturi shown on Fig. 6, but need not be described here nor is it pertinent to describe in detail the provision made for idling or for the control thereof.

To provide an additional supply of fuel for acceleration, a pump, actuated by the throttle, is

provided. The mixing chamber 23 isbored at position by the split elastic ring I22. A ball I23 in recess I24 forms a valve which opens to allow fuel to flow through channel I25 from the fuel chamber 52 into the pump but prevents reverse flow. To prevent too great a movement of the ball valve, it is retained in recess I24 by a diainetral web of the gasket I2I, shown at I26 in Fig. 8. .As Fig. 7 is a cross section on a polygonal line, it is not possible to show there how channel I25 is drilled fromthe outside of the casting, but reference I21 on Fig. 1 indicates both the start of said drilling and the plug used to close it.

A piston I28 is adapted to slide in the pump cylinder liner, being actuated by piston rod I29. Piston I28 is drilled and counterbored to form a seat I30 upon which diaphragm I3I is held by elastic split ring I32.

Adapted to reciprocate in a vertical hole in the mixing chamber body member and guided thereby is a pump rod I35 to which is riveted a bracket I36 provided with slot I 31 and downwardly bent ears I38. The piston rod I29 is formed with a head I33 and a neck I34. Diaphragm I3I is a sheet metal stamping provided with a stepped aperture wide enough at I to admit the end I64 of the piston rod and narrow at I GI, in the center of the diaphragm, so as to just admit the neck I34 of the piston rod. A spring I39 surrounds the piston rod and is compressed between diaphragm I3I and bracket I36; the top end of the spring is inserted between the ears I38 and the rod to hold the latter against lateral displacement; the lower end of the spring is likewise held by the upturned fingers I40 of the diaphragm and prevents lateral displacement of the lower end of the piston rod.

gers I40, is released and allowed to slip between said fingers and the piston rod.

The spring I39 is then compressed down to .per-' mit the insertion of the top of the piston rod into I claim: g

1. A piston, a piston rod, means to move said piston rod and means to secure said piston rod to said piston comprising an elastic friction member having a cylindrical friction surface parallel to said piston.

2. .A hollow piston having a diaphragm secured thereto, a piston rod'having a neck of reduced size, an aperture located centrally in said diaphragm to receive said neck, an ofi center aperture in said diaphragm wider than the piston rodand communicating with said first named the slot I31 of bracket I36, after which the spring is released to slip between ears I38 and the ton rod. 7

It will be seen that when the pump rod I35 is moved downwards, its movement is transmitted to the piston by the spring, as the piston rod is free to slide between the sides of slot I31. When the pump rod I35 is moved upwards, it is the piston rod that transmits the movement. It will also be seen that this arrangement provides a certain amount of flexibility, so that, the piston may be made a close fit into the cylinder liner, even though the latter may not be absolutely parallel to the hole that guides the pump rod I35.

The pump piston is actuated, through the pump rod I35, by a linkage made up of walking beam I4I, fulcrumed at I42 on the throttle body member, and terminating in a slot to engage pin I43 in the lower slotted end of pump rod I35, of lever I44 fastened to throttle shaft 33 and of connecting link I45, articulated on the walking beam at I46 and on lever I44 at one of the two (or more) holes I41 and I48.

Upon opening the throttle, this linkage will move the piston'downwards and the fuel in the the pump cylinder will be forced through channel I49, Fig. 7, past outlet valve I50 into slanted hole I5I and through accelerating nozzle I52, Fig. 6, into the main air conduit.

aperture, slidable means surrounding said piston rod and a pair, of protuberances on said diaphragm adjacent said second named aperture to hold said piston rod against lateral displacement when said slidable means are inserted between said rod and said protuberances.

3. A piston having a diaphragm secured there to, a piston rod having close to each of its ends a. portion of smaller sizethan the adjacent end, aneccentric aperture in said diaphragm wider than one end of said rod, a central aperture in said diaphragm connected to said eccentric aperture to admit only the rod portion of reduced size adjacent said end, slidable means surrounding each end of said rod, a pair of protuberances on said diaphragm to 'hold said rod against lateral displacement when said slidable means are inserted between said rod and said protuberances, a bracket having a slot to admit the portion of said piston rod of reduced size adjacent the other end thereof, a pair of protuberances on said bracket to hold said other end against lateral displacement when said slidable means are inserted between said rod and said protuberances and means to actuate said bracket.

4. A hollow cylindrical piston, a diaphragm held thereunto by frictional means in which the frictional surface is substantially parallel to the generatrices of the-cylindrical outer surfaces of the piston and means engaging said diaphragm to actuate said piston.

VICTOR R. I-EFTLER. 

